RE:Tesla Coil Grounding (was - Pig setup help.)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Jim Lux <jimlux-at-earthlink-dot-net> 

At 04:49 PM 3/15/2004 -0700, you wrote:
>Original poster: "John H. Couture" <couturejh-at-mgte-dot-com>
>
>All -
>
>To my knowledge all safety codes regarding the grounding of power
>transformers say the transformer case should be grounded to the green wire
>as defined in the codes.
>The main grounding question for Tesla coils is the connection of the green
>wire network to the secondary circuit (so-called RF) ground. Apparently
>coilers do it both ways, some connect and some do not connect. There are no
>codes for this type of connection. From a safety standpoint not connecting
>the two could be a hazard to humans. If you are taking sparks from a small
>or medium TC the line voltage could kill you if there is a spark between the
>primary and secondary coils.
>
>John Couture
>
>--

One technique that you could use when connecting the secondary ground (i.e. 
the RF ground) to the safety (i.e. green wire) ground is to connect it via 
a choke that has high impedance at 50 kHz (i.e. the TC operating frequency) 
but low impedance at 60 Hz.  The choke should be able to take the full 
fault current of the HV side of the transformer.

This way, if you get a primary to secondary short, via either dropping 
something conductive on it (it happens!) or with a streamer connecting in 
an ugly way, you've got a low impedance ground for the 60 Hz 
component.  The choke will keep the RF out of the building safety ground 
system (generally a "good thing").